Ventilator hood with collapsible bonnet



April 1963 w. A. SPEAR ETAL 3,087,411

VENTILATOR HOOD WITH COLLAPSIBLE BONNET Filed March 6, 1961 5 Sheets-Sheet 1 NVE TORS. BY 4. $4M

H TTURNEYS.

April 30, 1963 w. A. SPEAR ETAL 3,

VENTILATOR HOOD WITH COLLAPSIBLE BONNET Filed March 6, 1961 5 $heets-Sheet 3 IN VEN TORS- Z Arrow/ 's;

April 30, 1963 w. A. SPEAR ETAL 3,037,411

VENTILATOR HOOD WITH COLLAPSIBLE BONNET Filed March 6, 1961 5 Sheets-Sheet 4 April 30, 1963 w. A. SPEAR ETAL VENTILATOR HOOD WITH COLLAPSIBLE BONNET 5 Sheets-Sheet 5 Filed March 6, 1961 INVE TORS. 01%,, Q

J. nrraerl ey.

m N m. N?

United States Patent 3,087,411 VENTILATOR H001) WITH CGLLAPSIBLE BONNET Walter A. Spear, Charles Robert Turner, and Cleveland F. Meeker, Cincinnati, (lhio, assignors to Nutone, Ina, Cincinnati, Ohio, a corporation of New York Filed Mar. 6, 1961, Ser. No. 93,485 8 Claims. (Ci. 9S--II5) This invention relates to ventilators of the type which are installed above a cooking surface to exhaust or purify gases and odors rising therefrom. More particularly, it relates to a hood construction for such ventilators which includes a forwardly projecting bonnet adapted to be folded or swung away into a housing when the ventilator is not in use, whereby, the hood will occupy a minimum of usable space over the cooking surface, to provide a compact, unobtrusive unit.

A typical ventilator of the type to which this invention relates comprises a hood which is positioned, as nearly as possible, directly above the cooking surface for collecting the gases rising therefrom, a blower which accelerates the gases to an exhaust port or through filters which cleanse the air of odors and entrained grease and smoke particles. Such ventilators are usually although not necessarily mounted below overhead kitchen wall cabinets so that they will occupy relatively little usable wall :area.

The eificiency of ventilators of this type depends in substantial degree upon the area and position of the hood, which preferably should project over the entire cooking surface to collect most if not all of the column of gases rising from the range beneath it. The area enclosed by the hood should approach or equal the area of the cooking surface, or should at least be as large as is reasonably compatible with available space. The hood of a typical ventilator installation will project from several inches to more than a foot outwardly of the front of the main ventilator housing. Most of the time, when the ventilator is not in use, this hood serves no immediate purpose and is relatively obtrusive, projecting outwardly from the wall as it does.

This invention is predicated upon a ventilator hood construction which includes a frontal extension or bonnet which is movable between an open position, in which it in effect greatly increases the area and the air-collecting eifiClBIlCY of the hood, and a closed position, in which it folds into a housing afforded by the rear portion of the hood. The hood is especially adapted to be mounted beneath wall cabinets above a cooking surface, the bonnet folding into its housing in such manner that in closed position its top surface lies substantially in the plane of the front of the cabinets, and blends in or harmonizes attractively with the cabinets. In closed position thi hood is substantially more compact and less obtrusive than the conventional hoods of past constructions. Moreover, the air-collecting efiiciency of the hood with the bonnet in open position will equal or exceed the efiiciency of present types, since its area and position are not as limited as past constructions in repect to the optimum considerations.

A preferred embodiment of the hood of this invention includes a housing having top, rear, front, and side walls which is open at the bottom, and a bonnet having a sloping top panel and triangular end panels. The upper rear corners of the bonnet are slidably connected to the housing by pivots which ride in vertical slots at the front of the housing side walls. Foldability of the bonnet into the housing is efiected by means of a wheel and guide arm mechanism which causes the top panel of the bonnet to move into vertical position flush with the front edge of the housing as the bonnet is urged rearwardly toward the housing. This mechanism holds the bonnet in either closed or open position without the necessity "ice I 22 of utilizing positive catches, so that the bonnet can quickly be moved from either position to the other.

The invention may best be further described by reference to the accompanying drawings, in which:

FIGURE 1 is a front perspective of a typical installation of a ventilator in accordance with the invention, showing the bonnet in closed position;

FIGURE 2 is a front perspective of the installation shown in FIGURE 1, showing the bonnet in open position;

FIGURE 3 is a diagrammatic view showing the manner in which the bonnet cover insert may be removed in order to substitute a different insert for it;

FIGURE 4 is a transverse vertical cross-section taken on line 44 of FIGURE 1;

FIGURE 5 is an enlarged transverse cross-sectional view taken on line 5-5 of FIGURE 2, showing the manner in which the cover insert is held in place;

FIGURE 6 is an enlarged transverse vertical cross section taken on line 6-6 of FIGURE 2, showing the manner in which the bonnet is slidably secured to the housing;

FIGURE 7 is a fragmentary vertical cross-section taken on line 77 of FIGURE 6;

FIGURE 8 is a transverse vertical cross-section taken on line 88 of FIGURE 1;

FIGURE 9 is a transverse vertical cross-section taken on line 9-9 of FIGURE 2; and

FIGURE 10 is a horizontal cross-section taken on line 1tl10 of FIGURE 8.

Referring to the drawings in detail, a preferred ventilator 2i) embodying the principles of the invention is mounted below two conventional Wall cabinets 21 and 22 and between cabinets 23 and 24 at either end. Ventilator 20 generally comprises a housing 25 having a front panel 26 and a bonnet 27 which, in the open or extended position shown in FIGURE 2, projects forwardly from housing 25 below front panel 2s.

Housing 25 includes a rear wall 39, side or end walls 31 and 32, and a top wall 33 all of which may be fastened together by conventional means such as the angle brackets, tabs, and rivets shown. The housing 25 is open at the bottom to collect gases rising into it from a cooking surface below, not shown. A conventional blower, also not shown, is mounted inside the housing and accelerates the gases collected by the hood to an exhaust port.

Front panel 26 is secured to the top wall 33 of the housing at a position spaced rearwardly of the front edge of the top wall, and does not extend the full width of the housing to the side walls 31 and 32, for reasons explained more fully hereinafter, gaps or spaces 34 and 35 being defined between the ends of front panel 26 and housing side walls 31 and 32 respectively. As is best shown in FIGURE 6, an outwardly-extending flange 36 having a lip 37 is provided at the lower edge of front panel 26. Control knobs 4-0 and 41 for operating the blower may be mounted on front panel 26 as shown.

A mounting plate 42 is secured inside the housing adjacent each side wall 31 and 32 Each plate 42 encloses and mounts a mechanism designated generally by 44 for guiding and balancing the motion of the bonnet 27 when the latter is swung into or out of the housing 25, and for holding the bonnet in the closed or open positions shown in FIGURES l and 2.

As can best be seen in FIGURE 10, the left mounting plate 42 includes a rear portion 45 which is spaced inwardly of the housing side or end wall 31 by a right angular oifset portion 4-6, a section 47 which is facially secured to the inside surface of side wall 31, and an inwardly offset, vertically slotted strip 50 formed forwardly of portion 47. The rear edge of mounting plate 42 is secured to rear wall 30 by a bracket 51. The mounting plate which is secured to the other housing side wall 32 is similar.

Bonnet 27 has side walls 52 and 53 which are generally triangular in outline, between which a bonnet top panel 54 is secured by means of tabs and rivets as shown. A rigidifying rib 55 extends longitudinally across bonnet top panel 54. At the front of the bonnet a curved nose panel 56 is connected between the side panels 52 and 53 by means of tabs and rivets, and has a downwardly offset rear edge 57 which overlaps the front edge 60 of the bonnet top panel 54. At each side of the bonnet a trim strip 61 conceals the joints where top panel 54 and nose panel 56 meet side panels 52 and 53, and includes a pocket 62 at the position at which top panel 54 overlaps nos panel 56.

So that the color and ornamentation of the ventilator can readily be made consistent and harmonious with its surroundings, a decorative cover insert 63 is removably secured over bonnet top panel 54. This-insert 63 is rectangular in outline and is secured over the top panel between the trim strips 61, 61, and is held in place at its lower or forward edge by a cover strip 64 which is fastened through top panel 54 and nose 56 by means of spaced screws 65. The length of cover strip 64 is equal to the Width of the bonnet, the ends of the cover strip being received in the pockets 6'2, 62 formed in the trim strips 61, 61. The upper or rear edge of the decorative insert 63 is engaged under a forwardly extending flange 66 riveted at the rear edge of the bonnet.

By reason of the removability of the decorative cover insert 63, the manufacturer is enable economically to supply ventilators which will harmonize with a wide range of colors and decors. By selecting from a variety kept in stock a cover insert which is appropriate for a given installation and mounting that insert in the ventilator, the entire unit can readily be adapted to harmonize with different surroundings.

Installation of the cover insert 63 is effected by removing the nuts holding down screws 65, pulling the cover strip 64 upwardly and outwardly at its midsection so that the straight line distance between its ends is decreased, whereby its ends are disengaged from the pockets 62, 62 in the trim strips 61, 61, sliding the particular insert selected into position as shown FIGURE 3, and engaging its upper edge under flange 66. Cover strip 64 is then remounted and fastened in place to hold the insert securely in position.

The mechanism 44 whereby collapsibility of the bonnet 27 is effected may now be described. The mounting plate 42 which is at the left of the housing is provided with a detent 67 which comprises a bearing spacing a circular guide wheel 70 outwardly of the mounting plate in the chamber 71 which is defined between portion 45 of the mounting plate and housing side wall 31 (see FIGURE A pin 72 through detent 67 pivotally mounts the wheel 70 to plate 42. A second detent 73 is formed in the cover plate below detent 67 and holds a nylon rider 74 over which the wheel 70 can freely slide even if twisted downwardly about pin 72. It is convenient although not necessary to make plate 42 symmetrical about a horizontal plane through its mid-section by providing detents '75 and '76, which correspond to detents 67 and 73 respectively, so that the manufacturer can produce a single form of mounting plate which can be used at either end of the housing, the mounting plate which is at the right of the housing being identical to the plate 42 which is at the left of the housing, but oppositely oriented. Thus detents 75 and 76 serve no purpose in the plate 42 which is at th left of the housing but comprise the pivot and rider mounting of the plate which is at the right of the housing, the mechanisms 44 at each side of the housing being similar.

Guide wheel 70 is provided with two outwardly extending stops 80 and 81 which are preferably lanced from it. An elongated guide arm 82 is pivotally secured to guide wheel 70 by a pin 83 at a point between stops and 81. Arm 82 passes through a slot 79 in offset portion 46 of mounting plate 42, and is secured at its front end to bonnet 27 by a screw 84 which passes through an aperture 85 formed adjacent the slanting top edge of bonnet side panel 52 forwardly of the rear edge of the bonnet. A tension spring 86 is connected between one of a plurality of holes 87 in an offset portion 88 of guide arm 82 and the lower edge of mounting panel 42.

The offset front strip 50 of mounting plate 42 presents a vertical slot 96 extending to a point adjacent housing top panel 33. A T-headed bolt 93 is secured by a tab 94 to the upper corner of bonnet side panel 52, and slides in slot 90, as is best shown in FIGURE 6. The T-head of boits 93 preferably is rotatable so that the bonnet can be removed from the housing for shipment or cleaning as desired.

A lower slot 91 is provided in strip 50 for purposes of symmetry as previously explained, into which a nylon rider 92 is pressed. Rider 92 bears against the inside surface of bonnet end panel 52 to provide a sliding bearing for the bonnet as it is swung into or out of closed position. Similar structure is provided at the right end of the bonnet and housing.

FIGURES 8 and 9 illustrate the general operation of the guide mechanism 44 as the bonnet 27' is swung from 'open position, shown in FIGURE 9, to closed position,

shown in FIGURE 8. -As previously explained, each rear upper corner of the bonnet is secured to the housing 25 by a bolt 93 which, when the bonnet is in open position, is positioned at the bottom of slot 90. Guide arm 82 abuts stop 81 of wheel 70, so that counterlockwise rotation of wheel 70 is positively prevented. Being thus constrained, the bonnet is held by gravity in open position.

To close the bonnet into the housing, its nose 56 is manually swung downwardly and rearwardly so that bolt 93 moves upwardly in slot 90. As this occurs, guide arm 82 clears stop 81 and is moved rearwardly into chamber 71, pivoting simultaneously about bolt 84 by which it is connected to the bonnet and pin 83 by which it is connected to guide wheel 70. The guide wheel is constrained to turn counterclockwise about its pivot 72, bearing against rider 74 under the twisting torque applied to it by the guide arm, while T-head 93 moves upwardly in slot 99. This motion is arrested when stop 86 comes into contact with the guide arm, holding wheel 70 from further rotation and thereby fixing the angulation of arm 70 and bonnet 27. Spring 86 is then in tension, holding the guide arm in the position shown in FIGURE 8, so that the bonnet will remain in closed position.

When the bonnet is in closed position, its top panel 54 is positioned vertically, forward of housing front panel 26, substantially coplanar with the edges of the housing and the front of the cabinets between which it is mounted (see FIGURE 4). It thereby conceals the control knobs 40 and 41 and the interior of the housing. The bonnet side panels 52 and 53 extend into the housing through gaps 34 and 35 between the ends of housing front panel 26 and the left and right mounting plates 42, and it it for this reason that panel 26 does not extend the full width of the housing to the side walls.

To conceal the gaps or spaces 34 and 35 when the bonnet 1s in open position, flaps 95 and 96 are swingably mounted to housing top panel 33 at either end of front panel 26, and are urged by springs 97' toward the back surface of front panel 26. When the bonnet is in open position, these flaps are in the position shown in FIG- URES 6 and 7, the lower ends of the fiaps projecting downwardly behind the upper edge of the bonnet. When the bonnet is moved toward closed position, the rear edges 100 of the bonnet side panels 52 and 53 push the flaps 95 and 96 upwardly and inwardly to the position shown in FIGURE 4.

The hood is preferably made from sheet metal in accordance with conventional manufacturing techniques. It is adapted to receive a standard blower, filter and light, which can be mounted within the housing without interfering with the collapsibility of the bonnet. With bonnet in open position, the invention provides a hood which is of large enough area to be an effective collector, yet which can be collapsed so as to occupy relatively little usable space.

While the preferred embodiment of the invention has been described herein, the invention includes other embodiments and modifications falling within the scope of the claims which follow.

What is claimed is:

1. A hood for a ventilator adapted to be mounted above a cooking surface, said hood comprising a housing and a bonnet at the front of said housing, said housing comprising top, rear and side panels, means presenting vertical slots at the front of said housing adjacent each side thereof, said bonnet comprising generally triangular side panels having sloping upper edges and a top panel connected between said side panels, pivot means at the upper corners of said bonnet side panels slidable in said slots thereby connecting said bonnet to said housing, a guide wheel interiorly adjacent each housing side panel, means mounting each wheel for rotation about a horizontal axis, an arm pivotally connected between an off-center point on each said wheel and a bonnet side panel, and stops on said wheels permitting limited rotation of said wheels with respect to said arms, one of said stops on each wall engaging the underside of each respective arm between the connection of said arm to said bonnet side panel and the connection of said arm to said wheel to limit rearward movement of said bonnet towards said housing, whereby when said bonnet is simultaneously tipped about said pivot means and moved rearwardly towards said housing said wheels and arms guide the bonnet top panel into a vertical position such that the top edge of said bonnet top panel is adjacent the front edge of said housing top panel.

2. A hood for a ventilator adapted to be mounted above a cooking surface, said hood comprising a housing and a bonnet at the front of said housing, said housing comprising top, rear and side panels, means presenting a vertical slot at the front of said housing at each side thereof, each said slot extending from a point adjacent said housing top panel to a point above the midsection of said housing side panel, said bonnet comprising two side panels having sloping upper edges and a top panel connected between said side panels, a T-head bolt at each upper corner of said bonnet, each bolt being slidably received in a slot thereby connecting said bonnet to said housing, a guide wheel interiorly adjacent each housing side panel, means mounting each wheel for rotation about a horizontal axis, an arm pivotally connected between an off-center point on each wheel and said bonnet side panel forwardly of said bolt, and stops on said wheels permitting limited rotation of said wheels with respect to said arms, one of said stops on each wheel engaging the undersides of the respective arms between the points of connection of said arms to said bonnet side panels and the pivotal connections of said arm to said wheels to limit rearward movement of said bonnet toward said housing, whereby when said bonnet is simultaneously tipped about said bolts and moved rearwardly towards said housing said wheels and arms cause said bolts to move upwardly in said slots thereby guiding the bonnet top panel into a vertical position such that the top edge of said bonnet top panel is adjacent the front edge of said housing top panel.

3. A hood for a ventilator adapted to be mounted above a cooking surface, said hood comprising a housing and a bonnet at the front of said housing, said housing comprising a top wall, a front wall, a rear wall and two side walls, said walls being interconnected, said front wall having a lower edge which is above approximately the midsection of said side walls, said front wall defining a space at each side 6 thereof inwardly of said side walls, means presenting a vertical slot at each side of said housing forwardly of said front wall, each slot extending from a point adjacent said top Wall to a point adjacent the lower edge of said front wall, said bonnet comprising two generally triangular side panels having sloping upper edges and a top panel connected between said side panels, pivot means at the upper corner of each side panel, each said pivot means being slidably connected in a slot, a guide wheel interiorly adjacent each side wall, means mounting each wheel for rotation about a horizontal axis, an arm pivotally connected between an off-center point on each Wheel and a point on a side panel which point is forward of said pivot means, stops on each wheel on either side of said off-center point permitting limited rotation of said wheels with respect to said arms, a stop on each wheel engaging the undersides of the respective arms at a point between the point of connection of said arm to said side panel and to said wheel to limit rearward movement of said bonnet toward said housing, whereby when said bonnet is simultaneously tipped about said pivot means and moved rearwardly towards said housing said wheels and arms cause said pivot means to move upwardly in said slots thereby guiding said top panel forwardly of said front wall into a vertical position such that the top edge of said top panel is adjacent the front edge of said top wall, said side panels extending through said spaces into said housing.

4. A ventilator hood comprising a housing and a bonnet at the front of said housing, said housing being defined by top, rear, front and two side walls, means connecting said walls together, said front wall extending downwardly from said top wall, the width and height of said front wall being less than the width and height of said housing, a space being presented between each side edge of said front wall and said side walls, a rearwardly swingable flap covering each said space, said housing being open at the front below said front wall and at the bottom, said bonnet comprising two generally triangular side panels and a top panel connected between said side panels, a pivot extending outwardly at the upper corner of each side panel, slot means presented by said housing at the front thereof permitting rotational and limited vertical motion of each pivot, a guide wheel adjacent each said side wall, means pivotally mounting each guide wheel for rotation about a horizontal axis, a guide arm connected between an offcenter point of each guide wheel and the corresponding side panel of said bonnet, stop means on each wheel permitting limited rotation of each guide wheel, said stop means engaging the underside of said arm at a point between the connection of said arm to said bonnet and to said wheel during rearward movement of said bonnet toward said housing, whereby said bonnet is movable between an open position in which its top panel projects slopingly forward from the lower edge of said front wall and a closed position in which said bonnet top panel is in vertical position adjacent the front edge of the housing top wall forwardly of said front wall, said side panels extending through said spaces into said housing and swinging said flaps reawardly.

5. A hood for a ventilator adapted to be mounted above a cooking surface, said hood comprising a housing and a bonnet at the front of said housing, said housing comprising top, rear and side walls, means connecting said walls together, means presenting vertical slots at the front of said housing adjacent each side wall thereof, said bonnet comprising a pair of side panels, a top panel connected between said side panels, a decorative insert panel overlying said top panel, means removably securing said insert panel to said bonnet, pivot means at the upper corners of said side panels slidably received in said slots thereby connecting said bonnet to said housing, a guide wheel interiorly adjacent each said side wall, means mounting each wheel for rotation about a horizontal axis, an arm pivotally connected between an off-center point on each said wheel and a side panel, and stops on said wheels permitting limited rotation of said wheels with respect to said arms, one of said stops engaging the underside of one said arm between the connection of said arm to said side panel and to said wheel to limit rotation of said wheel as said bonnet is moved rearwardly, whereby when said bonnet is simultaneously tipped about said pivot means and moved rearwardly towards said housing said wheels and arms guide said top panel into a vertical position such that the top edge of said insert panel is adjacent the front edge of said top wall, said insert panel thereby forming a decorative front for said hood.

6. A hood for a ventilator adapted to be mounted above a cooking surface, said hood comprising a housing and a bonnet at the front of said housing, said housing comprising a top wall, a rear wall and two side Walls, means connecting said walls together, means presenting a vertical slot at each side of said housing adjacent the front thereof, said bonnet comprising a pair of side panels having sloping upper edges, a top panel connected between said side panels, a forwardly projecting flange at the upper edge of said top panel, a decorative insert panel overlying said top panel, the upper edge of said insert panel being engaged under said flange, a removable strip securing the lower edge of said insert panel to said bonnet, pivot means at the upper corners of said side panels slidable in said slots thereby connecting said bonnet to said housing, a guide wheel interiorly adjacent each side wall, means mounting each wheel for rotation about a horizontal axis, an arm pivotally connected between an off-center point on each said wheel and a side panel, and stops on said wheels permitting limited rotation of said wheels with respect to said arms, one of said stops engaging the underside of one of said arms between the connection of said arm to said side panel and to said wheel to limit rearward movement of said bonnet toward said housing when said bonnet is in vertical position, whereby when said bonnet is simultaneously tipped about said pivot means and moved rearwardly towards said housing said wheels and arms guide said top panel into a vertical position such that the top edge of said in sert panel is adjacent the front edge of said top wall, said insert panel thereby forming a decorative front for said hood.

7. A hood for a ventilator adapted to be mounted above a cooking surface, said hood comprising a housing and a bonnet at the front of said housing, said housing comprising a top wall, a rear wall and two side walls, means connecting said walls together, means presenting a vertical slot at each side of said housing adjacent the front thereof, said bonnet comprising a pair of side panels having sloping upper edges, a top panel connected between said side panels, a curved nose panel connected between said side panels forwardly of said top panel, a forwardly projecting flange at the upper edge of said top panel, a decorative insert panel overlying said top panel, the upper edge of said insert panel being engaged under said flange, a removable strip securing the lower edge of said insert panel to said bonnet between said top panel and nose panel, outwardly extending pivot means at the upper corner of each side panel, said pivot means being slidably received in a slot thereby connecting said bonnet to said housing, a guide Wheel interiorly adjacent each side wall, a mounting plate spaced inwardly of each side wall, each said plate mounting a wheel for rotation about a horizontal axis, an arm pivotally connected between an off-center point on each said wheel and a side panel, each said wheel presenting a pair of stops permitting rotation of said wheels with respect to said arms, one of the stops on each weel engaging the underside of the arm connected to the respective wheel between the connection of said arm to said side panel and to said wheel to limit rearward movement of said bonnet toward said housing in vertical position, and spring means connected to said guide arms counter-balancing the weight of said bonnet, whereby when said bonnet is simultaneously tipped about said pivot means and moved rearwardly towards said housing said wheels and arms guide said top panel into a vertical position such that the top edge of said insert panel is adjacent the front edge of said top wall, said insert panel thereby forming a decorative front for said hood.

8. A hood for a ventilator adapted to be mounted above a cooking surface, said hood comprising a housing and a movable bonnet at the front of said housing, said housing having an open frontal area, means on said housing presenting a vertical slot at each side of said open frontal area, said bonnet comprising spaced side panels having forwardly and downwardly sloping upper edges and a top panel connected between said side panels, pivot means at the upper corners of said side panels slidable in said slots thereby connecting said bonnet to said housing for movement in said frontal area, a guide wheel pivotally mounted to said housing at each side of said open frontal area, said guide wheels being mounted for rotation about a longitudinal horizontal axis, a pair of arms each pivotally connected between an oif-center point on one of said wheels and one of said side panels, and a .stop on each wheel permitting limited rotation of said wheel with respect to the arm connected to it whereby when said bonnet is simultaneously tipped about said pivot means and moved rearwardly towards said housing said wheels and arms guide the bonnet top panel intosubstantially vertical position in said frontal area of said housing, each stop engaging the underside of its respective arm at a point between the connection of said arm to the side panel and the point of connection of said arm to the wheel to limit rearward movement of said bonnet, and means limiting forward movement of said bonnet and supporting said bonnet in forwardly extended position.

References Cited in the file of this patent UNITED STATES PATENTS 2,341,245 Sonntag Feb. 8, 1944 2,582,884 Nicol Jan. 15, 1952 FOREIGN PATENTS 1,088,458 France Mar. 8, 1955 157,744 Sweden Feb. 5, 1957 

1. A HOOD FOR A VENTILATOR ADAPTED TO BE MOUNTED ABOVE A COOKING SURFACE, SAID HOOD COMPRISING A HOUSING AND A BONNET AT THE FRONT OF SAID HOUSING, SAID HOUSING COMPRISING TOP, REAR AND SIDE PANELS, MEANS PRESENTING VERTICAL SLOTS AT THE FRONT OF SAID HOUSING ADJACENT EACH SIDE THEREOF, SAID BONNET COMPRISING GENERALLY TRIANGULAR SIDE PANELS HAVING SLOPING UPPER EDGES AND A TOP PANEL CONNECTED BETWEEN SAID SIDE PANELS, PIVOT MEANS AT THE UPPER CORNERS OF SAID BONNET SIDE PANELS SLIDABLE IN SAID SLOTS THEREBY CONNECTING SAID BONNET TO SAID HOUSING, A GUIDE WHEEL INTERIORLY ADJACENT EACH HOUSING SIDE PANEL, MEANS MOUNTING EACH WHEEL FOR ROTATION ABOUT A HORIZONTAL AXIS, AN ARM PIVOTALLY CONNECTED BETWEEN AN OFF-CENTER POINT ON EACH SAID WHEEL AND A BONNET SIDE PANEL, AND STOPS ON SAID WHEELS PERMITTING LIMITED ROTATION OF SAID WHEELS WITH RESPECT TO SAID ARMS, ONE OF SAID STOPS ON EACH WALL ENGAGING THE UNDERSIDE OF EACH RESPECTIVE ARM BETWEEN THE CONNECTION OF SAID ARM TO SAID BONNET SIDE PANEL AND THE CONNECTION OF SAID ARM TO SAID WHEEL TO LIMIT REARWARD MOVEMENT OF SAID BONNET TOWARDS SAID HOUSING, WHEREBY WHEN SAID BONNET IS SIMULTANEOUSLY TIPPED ABOUT SAID PIVOT MEANS AND MOVED REARWARDLY TOWARDS SAID HOUSING SAID WHEELS AND ARMS GUIDE THE BONNET TOP PANEL INTO A VERTICAL POSITION SUCH THAT THE TOP EDGE OF SAID BONNET TOP PANEL IS ADJACENT THE FRONT EDGE OF SAID HOUSING TOP PANEL. 